Monday, June 8, 2015

Climates are exceedingly complex and take place over very long time frames. Compounding those problems is the fact that is it FAR easier to measure changes over time than it is to predict changes in the future. For example, we know a lot of glaciers have melted releasing fresh water into areas of the ocean that have become a whole lot less salty. What we don't know is what that development portends.

We DO know that burning carbon increases greenhouse gasses that trap more of the sun's energy in the atmosphere. Adding more energy to a closed system usually means trouble. But we don't know how much of the extra energy goes into the air and how much into the water. And this uncertainty alone has made a lot of predictions look pretty silly.

Outside of predicting that we are probably not going to like the outcomes produced by an atmosphere with more energy, it would probably be prudent for the scientific community to not be so specific. Not only can such overly precise predictions come back to bite them, but there is PLENTY of work merely explaining how greenhouse gasses are produced and why pumping mega-tons into the atmosphere must be avoided, etc.

What follows is two explanations for why some of those ultra-hot temps didn't show on schedule.

Global warming 'pause' didn't happen, study finds

Reassessment of historical data and methodology by US research body debunks ‘hiatus’ hypothesis used by sceptics to undermine climate scienceThe year 2014 was Earth’s warmest in 134 years of records, according to an analysis of surface temperature measurements by Nasa scientists. In a separate, independent analysis, scientists at the National Oceanic and Atmospheric Administration also found 2014 to be the warmest on record. Photograph: GISS/NASA

Karl Mathiesen 5 June 2015

Global warming has not undergone a ‘pause’ or ‘hiatus’, according to US government research that undermines one of the key arguments used by sceptics to question climate science.

The adjustments to the data were slight, but removed a flattening of the graph this century that has led climate sceptics to claim the rise in global temperatures had stopped.

“There is no slowdown in warming, there is no hiatus,” said lead author Dr Tom Karl, who is the director of Noaa’s National Climatic Data Centre.

Dr Gavin Schmidt, a climatologist and the director of Nasa’s Goddard Institute for Space Studies said: “The fact that such small changes to the analysis make the difference between a hiatus or not merely underlines how fragile a concept it was in the first place.”

The results, published on Thursday in the journal Science, showed the rate of warming over the past 15 years (0.116C per decade) was almost exactly the same, in fact slightly higher, as the past five decades (0.113C per decade). Adapted from Noaa National Centers for Environmental Information

In 2013, the UN’s most comprehensive report on climate science made a tentative observation that the years since 1998 had seen a “much smaller increasing trend” than the preceding half century. The results highlighted the inadequacy of using the global mean surface temperature as the primary yardstick for climate change.

Karl said: “There’s been a lot of work done trying to understand the so-called hiatus and understand where is this missing heat.”

“Those studies are all quite valid and what they suggest is had those factors not occurred the warming rate would even be greater than what we report,” said Karl.

Dr Peter Stott, head of climate monitoring and attribution at the UK’s Met Office, said Noaa’s research was “robust” and mirrored an analysis the British team is conducting on its own surface temperature record.

“Their work is consistent with independent work that we’ve done. It’s within our uncertainties. Part of the robustness and reliability of these records is that there are different groups around the world doing this work,” he said.

But Stott argued that the term slowdown remained valid because the past 15 years might have been still hotter were it not for natural variations.

In the coming years the world is expected to move out of a period in which the gradient of warming has not slowed even though the temperature has been moderated. This means “we could have 10 or 15 years of very rapid rates of warming,” he said.

“Even though the observed estimate is increased, over and above that there is plenty of evidence that the rate of warming is still being depressed,” he said. “The caution is around saying that that is our underlying warming rate, because the climate models are predicting substantially higher rates than that.”

Noaa’s historical observations were thrown out by unaccounted-for differences between the measurements taken by ships using buckets and ships using thermometers in their engine in-takes, the increased use of ocean buoys and a large increase in the number of land-based monitoring stations.

“Science can only progress based on as much information as we have and what you see today is the most comprehensive assessment we can do based on all the information that’s been collected,” said Karl.

Schmidt called the new observations “state of the art” and said Nasa had been in discussions with Noaa about how to incorporate the findings into their own global temperature record.

Prof Michael Mann, whose analysis of the global temperature in the 1990s revolutionised the field, said the work underlined the conclusions of his own recent research.

“They’ve sort of just confirmed what we already knew, there is no true ‘pause’ or ‘hiatus’ in warming,” he said. “To the extent that the study further drives home the fact ... that global warming continues unabated as we continue to burn fossil fuels and warm the planet, it is nonetheless a useful contribution to the literature.”

Bob Ward, policy and communications director at London’s Grantham Research Institute, said the news that warming had been greater than previously thought should cause governments currently meeting in Bonn to act with renewed urgency and lay foundations for a strong agreement at the pivotal climate conference in Paris this December.

“The myth of the global warming pause has been heavily promoted by climate change sceptics seeking to undermine the case for strong and urgent cuts in greenhouse gas emissions,” said Ward.

Since scientists began to report a slower than expected rate of warming during the last decade, climate sceptics have latched on to the apparent dip in order to question the validity of climate models.

Last February, US Republican presidential candidate Ted Cruz told CNN: “The last 15 years, there has been no recorded warming. Contrary to all the theories that – that they are expounding, there should have been warming over the last 15 years. It hasn’t happened.”

Cruz’s rival for the Republican nomination, Jeb Bush, was using the pause to argue for inaction as early as 2009.

The Global Warming Policy Foundation (GWPF), the UK thinktank set up by Nigel Lawson to lobby against action on climate change and which hosts a flat-lining temperature graph on the masthead of its website, was dismissive of the study.

Dr David Whitehouse, an astrophysicist and science editor for the GWPF, said: “This is a highly speculative and slight paper that produces a statistically marginal result by cherry-picking time intervals.” He claimed the temperature graph was at odds with those of the Met Office and Nasa, despite both organisations saying the new study’s results were consistent with their data. more

Earth wins time as land and seas absorb more carbon

Climate change has intensified more slowly than scientists had expected because the continents and oceans are absorbing more atmospheric carbon dioxide.

LONDON, 17 May, 2015 − Half of all the carbon emissions from burning fossil fuels remain in the atmosphere. The good news is that only half remain in the atmosphere, while the rest have been taken up by the living world and then absorbed into the land, and the ocean. That is, as carbon dioxide levels in the atmosphere have risen, so also has the planet’s capacity to soak up atmospheric carbon.

The implication is that what engineers call “positive feedback” – in which global warming triggers the release of yet more greenhouse gases into the atmosphere to accelerate yet further warming – doesn’t seem to be at work yet.

The implication, too, is that the world’s governments still have time to launch determined programmes to sharply reduce fossil fuel use, and switch to wind, solar and other renewable energy sources before climate change disrupts the planet’s food security and exacts what could be a devastating toll on the biosphere.

But most climate scientists know all this anyway: the real significance of a new study in the journal Biogeosciences is that US and British scientists have narrowed some of the uncertainties in what climate scientists like to call the carbon budget: how much gets into the atmosphere, where it goes, and how long it stays.

That is because although the big picture – that carbon dioxide levels in the atmosphere are beginning to rise steeply – has been confirmed repeatedly by systematic measurements since 1956, the potential margin of error has been considerable.

“There is no question that land and oceans have, for at least the last five and half decades, been taking up about half of the carbon emitted each year. The outstanding question is, Why?” said Richard Houghton of the Woods Hole Research Center in Massachusetts, one of the authors.

“Most of the processes responsible for that uptake would be expected to slow down as the Earth warms, but we haven’t seen it yet. Since the emissions today are three times higher than they were in the 1960s, this increased uptake by land and ocean is not only surprising; it’s good news.

“Without it, the concentration of CO2 in the atmosphere would be twice what it is, and climate change would be much farther along. But there’s no guarantee that it will continue.”

The carbon budget is an integral part of the climate puzzle: all simulations of how climate will change with increasing emissions from fossil fuels depend on an understanding of how much carbon dioxide concentrates in the atmosphere and what happens to it after that.

But these have been studies of small pieces of the big puzzle. What the Biogeosciences authors did was to refine two global uncertainties. One is how much fossil fuel is burned each year and the other is how much is stacking up in the atmosphere.

Both sound simple, but the first question is complicated by differences in the ways nations maintain their own energy inventories, and the way they report the details, and the second depends on how the use of land has changed, how the oceans are responding to higher levels of acidification and how carbon dioxide levels vary according to region, and to season.

With greater certainty in the answers to the second question – which began with one single set of measurements at the top of a mountain in Hawaii now replicated worldwide – researchers found they could make more sense of the first question, and narrow the uncertainties to a point where they could write that they were “93% confident that terrestrial C uptake has increased and 97% confident that ocean C uptake has increased in the last five decades.

“Thus it is clear that arguably one of the most vital ecosystem services currently provided by the biosphere is the continued removal of approximately half of atmospheric CO2 emissions from the atmosphere.” more